Automatic touchfree dispensers (or “hands-free dispensers”) for paper towels are known on the market. The hands-free dispensers are electronically manoeuvred, they store and advance the paper towel with different kinds of control devices, sensors and power sources available. Without touching the dispenser, the user can get a paper towel that is fed automatically by the electronic dispenser. Dispensers like this are commonly used in public lavatories for dispensing paper towels to users. The most common type of a powered, hands-free dispenser is a roll dispenser that users sensors to initiate the mechanisms for advancing the towel such that the subsequent sheet is presented to the user.
Rolls of paper towels are often heavy and there is a friction and resistance for unrolling the paper. Especially when the roll is accelerated there is a high demand of energy. Consequently, there is a need for a strong paper in order to withstand the force necessary to make a full heavy roll to start rotating. A strong paper usually has drawbacks in that the softness of the paper is low. In addition, hands-free dispensers for rolled paper towels demand a large amount of space due to the relatively large volume of the heavy paper rolls.
As an alternative to rolls of paper towels, US2011/0101020, WO 2011/045493, EP 1 830 687 all disclose dispensing units comprising a housing for holding a pile of a continuous length of accordion-like folded web of towels. The dispenser comprises an access opening to the pile, a dispensing opening for the web of towels, a feeding mechanism comprising a member for controlling the dispensing of the web of towels, and a drive unit. Bundles of paper towels with connecting means therebetween are insertable through the access opening into the housing in the dispensing unit and may be added to the bottom of the pile. The web of towels is dispensable from the upper part of the pile by the feeding mechanism, which positions the web of towels in a starting mode in the dispensing opening. This solution enables feeding of a large amount of wipe products while avoiding the problems relating to the weight of a heavy paper roll or large pile. Preferably, the folded web material comprises a double folded perforated web material, where two perforated webs are interfolded, such that the perforations are arranged in an off-set relationship to each other. A separation unit enables the wipe products to be separated at the lines of weakness when the web is pulled by the user. This feature will allow the feeding of the products to be performed manually by the user, hence avoiding any additional arrangements of the dispensers such as electrical power.
However, to realize the dispenser as described above a number of problems must be solved, including separating the webs correctly along the perforation lines, feeding the next portion of the web to be separated to the separation unit, and presenting the leading end of the web to the next user. Furthermore, separation shall be possible for different types of web materials and web materials having different lengths between the perforation lines.
GB 2 433 248 describes a dispenser for feeding a rolled material comprising two perforated webs, wherein the perforations are in offset relationship. The dispenser comprises two profiled rollers being arranged to form a non-linear nip, applying pressure to the sheet material so that the lines of weakness of the web material would burst. The nip is formed by protrusion elements of different sizes arranged on two rollers. It is shown that the surfaces of each pair of opposing protrusion elements are always in contact with each other.
WO 2011/1149393 describes a dispenser for feeding a rolled tissue or nonwoven material, which may be provided with perforations. A problem with perforated webs is defined, relating to the fact that the web tends to break at every perforation, but that the user might sometimes wish to use a long section of web and sometimes a short section of web. For feeding the web in the dispenser, there is provided a drive roller and an engaging roller. The drive roller and the engaging roller are arranged such that an undulated passage is defined between the protrusion elements on the rollers. It is stated that the undulated passage ensures that the dispensing end of the web is in contact with both the drive roller and the engaging roller in the passage. Also, a pulling force exerted substantially straight out from the dispensing passage is distributed evenly over a central portion of the web, which results in that the web will not break even if perforated, until the user chooses to apply a force sideways. The separation is thus done by the user rather than by the dispenser itself.
It is therefore an object of the present invention to provide a separation unit eliminating the above-mentioned problems.